package Demo3;

public class Computer {
    public void open() {
        System.out.println("打开电脑");
    }
    public void close() {
        System.out.println("关闭电脑");
    }

    public void useUsb(IUSB usb) {
        usb.openDevice();
        if(usb instanceof Mouse) {
            ((Mouse) usb).click();
        }else if(usb instanceof KeyBoard) {
            ((KeyBoard) usb).input();
        }
        usb.closeDevice();
    }
}
